A New Approach for Enhanced Reservoir Characterization and Petrophysical Parameters Estimation in Northeast Sanan Field in Western Deserts of Egypt

Abstract

The conventional hydrocarbon resources in the Egyptian western deserts are characterized by high heterogeneity. In turn, petrophysics characterizes heterogeneous rocks with different flow units and rock types. Knowledge of the rock's petrophysical properties including permeability, porosity, pore throat radius, and lithology Index is essential for developing reservoir characterization. It is well known that this knowledge is best gained from coring samples; however, coring for all wells is not economical. Subsequently, prediction of these parameters in uncored intervals is required with accurate estimation rates. Petrophysics applied several techniques for these purposes including the use of NMR methods however, such methods are not cost-effective nor time-saving. From these perspectives, this paper aims to develop a new approach through which heterogeneous rock intervals are divided into more homogeneous flow units depending on the lithology index and pore throat radius. Also, it aims to accurately determine the lithology index without the need to apply a Mercury Injection Capillary Pressure “MICP” test which eventually destroys the core properties and implies that the core sample is not applicable for any other purposes. Moreover, the study aims to provide an approach for calculating the most accurate value of the Flow Zone Indicator “FZI” without the need to use Nuclear Magnetic Resonance “NMR” methods which are very costly and time-consuming. In conclusion, for rock typing comparison purposes, other rock typing techniques were applied to the same data as Amaefule et al, Discrete Rock Typing “DRT”, Winland R35, and Permeability Grouping techniques. Results showed that the developed technique “Litho-R35” could identify 11 rock types with a high regression coefficient R2. Besides, an equation was developed to estimate permeability with a very good regression coefficient (R2=0.9992) when compared with the core measured data. Additionally, the most accurate value of FZI was acquired without the use of NMR methods. Eventually, the developed technique serves for better rock typing practices and accurate estimation of varying petrophysical properties in uncored intervals.